502 RC-W Elasto-Kote Metal Roofing System
PREPARATION AND APPLICATION GUIDELINES
1. All fasteners should be re-tightened or replaced as necessary. Stripped fasteners must be replaced with larger fasteners. All fasteners must include a neoprene washer.
2. The roof should be power washed maintaining a minimum of 3000 psi of working pressure. This should remove all dirt, dust and waste products, i.e. grease, animal fats, solvents, loose roofing products and any air borne pollutants.
3. Rusted through panels or section must be replaced.
4. Heavily rusted areas must be wired brushed down to clean, stable metal.
5. All horizontal seams must be treated in the following manner:
A.) Peal back the release sheet and apply Karnak Metal Seam Sealing Tape exactly to the horizontal seam. Try not to remove as this may damage the Metal Seam Sealing Tape. Do not stretch tape.
B.) Press down firmly starting at the center and working towards the outside edge, removing bubbles. Slight wrinkling should not affect the performance of the seal. Edges must be free of fishmouths, uplifts and tunnels.
C.) Press down firmly where tape goes over any fasteners.
D.) Finish seam by applying Karnak 502 Seam Sealer over the taped seam. Apply 502 Seam Sealer with a 3" brush. Apply at an average thickness of 1/16" to completely cover the polyester face fo the Metal Seam Sealing Tape and feather out. Coverage of 502 Seam Sealer is approximately 50 lineal feet per gallon.
6. All vertical seams if tight, should only receive a 2" wide application of 502 Seam Sealer. If seams are open, follow treatment for horizontal seams as described above.
7. Any fasteners in the field of the roof not already protected as part of a seam detail must receive a dollop (swirl coat) of 502 Seam Sealer to completely enclose the fastener. Coverage of 502 Seam Sealer is approximately 250 fasteners per gallon.
8. All protrusions and curbs should be flashed with Metal Seam Sealing Tape and 502 Seam Sealer, following good roofing practices and roofing industry standards. The Metal Seam Sealing tape and 502 Seam Sealer may be overlapped by 1" for addressing wider repairs.
9. Allow all repairs and seam details with Metal Seam Sealing Tape and 502 Seam Sealer to cure for 24-48 hours.
10. Apply Karnak 502 RC-W Self-Priming Base Coat at a rate of 1.5 gallons per 100 sq.ft. Allow the base coat to dry a minimum of 24 hours before applying the finish coating.
11. Finally, apply Karnak 502 RC-W Elasto-Kote Finish Coat at a rate of 1.5 gallons per 100 sq.ft. and allow to dry.
Note: Field measurements are essential because actural square footage of corrugated metal roofs are more than conventional flat roofs. There could be as much as 15% - 20% difference in the total square footage. Do not apply over asphaltic or aluminum coated surfaces.